As I learn and read more about type design, one area of continued interest for me is the lowly/mighty Serif. It's always facinating to me to see what aspect of their function authors highlight.

For example: Counterpunch by Fred Smeijers
On pages 30-32 (and elsewhere) he talks about how serifs promote good word image by defining the space between letters and the counters within letters. This helps designers as we try to balance the internal and external space. Smeijers suspects it helps readers too ...

I'd like to do a comprehensive read on the topic. Can you recommend credible books or other resources that give insight here?

Randy, your subject line lead me to believe something different. :^P I thought you were going to go on and on about why there is no reason for serifs.

I don't have that book here at work, but doesn't it have a bibliography? That might be a good place to start. In fact, any of type book worth reading should have a good -- at least decent -- bibliography.

There are a number of good articles dealing with the role of serifs in Gunnar Swanson's collection of essays Graphic Design & Reading

...promote good word image by defining the space between letters and the counters within letters.

For open bowls (counters) yes. Either Fred's terminology is innacurate, or you may have paraphrased rather than quoting. Strictly speaking only fully closed bowls contain counters. But that's a hard-edged technical definition I suspect some tpyographers might dispute.

Randy, The Serif is Dying thread at Typographica from 2002 offers clues and views from prominent contemporary typographers. Some of it might be of interest. Problem is the discussion starts off with serifs then morphs into a detailed dialog on readability, which is a subject in itself.

Side note: I'd be interested to see the Times Roman Sans in the linked study that was equally well received as Times Roman Serif. The only difference being the serifs trimmed off in the "sans" version.

Randy, the bulk of justifications of the serif, even by reputable and otherwise excellent sources is pretty hollow. Reasons like "they create train tracks for the eyes", "they define the line so that line-returns are easier", and "they define the ends of strokes better" are the sad norm - sad because these things don't hold up for 10 seconds once you really delve into reading.

Smeijers is probably the most reputable, mainstream author who has come closest to what I think makes sense - and that's pretty rare unfortunately. He's talking about notan, and that's the key. But he still doesn't go far enough. The articles by Peter and myself in Typo 13 try to go deeper, although they don't really focus on serifs. Serifs help essentially because they increase the convergence of letters into boumas. In comparison, the only way sans fonts can attempt this is by making the letters too close, and of course that backfires.

A paradoxical extension of this is that serifs help by making letters
less themselves (and more parts of boumas). It's possible to see this
as parallel to the belief that a real text font needs a certain ugliness.

BTW:
1) One thing that has yet to be really addressed is the semi-serif.
2) You might be interested to know that Bloemsma went through
a love/hate thing with serifs - he was conscientious enough that
he needed to justify them (as you seem to be trying to do) instead
of just leaning on them blindly or shunning them.

Smeijers is probably the most reputable, mainstream author
What he is saying makes sense. And I agree he is talking about serifs in the context of notan and boumas without the vocabulary. I'd like to read your articles in Typo 13. Can you send me the text? Or is it still available?

I wonder if there aren't at least several things fighting sans serif typography for text.
1. The word shapes break down into letter shapes when you space sans serif type optimally for text (by harmonizing the space between letters with the space inside letters). This is another way of saying what you said above.
2. In some sanserif type (and also in modern serif typography) the vertical stress accentuates the break down.
3. Defining word shape requires a solid perception of x-height and baseline. This is kind of like the traintrack idea, but more at a word level than a scentence level. Sans serif type really lacks some definition at the baseline, but also the x-height.

One thing that has yet to be really addressed is the semi-serif.
This is what got me started. I'm reworking a semi serif design that was laying around on my hardrive. What I would like to achieve is essentally "sans serif" for longER text, facilitated by the addition of serifs at critical locations. What I've found thus far is that it's very difficult not to allow stylistic choices to trump the schema that I'm trying to work out. I'm finding it very interesting.

I was messaging with Paul Hunt about opentype this afternoon and we stumbled on a further idea together. What about a semi-serif opentype face, that contextually places serifs based on neighboring glyphs? An interesting concept that could potentially allow a font to reflect this dialogue in a new way.

Typo 13: I guess the PDFs of back issues are not currently available.
Not sure if they'll be back or not - the "discussion" section of their
site seems to imply they will. But I can send you a print copy if you
give me your ground address - hpapazian thatsymbol gmail dot com.

My primary interest in the role of serifs in reading concerns their possible contribution to overcoming lateral masking in the parafovea. This is non-intuitive, but research has shown that adjacent forms that have connecting strokes are less affected by lateral masking that forms that are separated by gaps. Lateral masking is the phenomenon whereby which a form perceived in the parafovea that is adjacent to another form or between two other forms is harder to recognise than an isolated form. Obviously lateral masking has a huge impact on our ability to recognise any letter shapes in the parafovea, but some recent research indicates that serifs, by bridging the gap between the letters, may reduce the effect of lateral masking. As I say, this is counter intuitive, since it is the proximity of the letters that produces lateral masking in the first place. Note that this isn't counter to Hrant's comments about serifs helping convergence of letters into boumas: it explains in part how they do this in the parafovea, by overcoming the lateral masking that obscures the 'role architecture', to use Peter Enneson's phrase, of the constituent letters.

In 'Letters of Credit,' which you probably already know, Walter Tracy makes a number of interesting comments on the sans serif. One of these is that the sans needs to be more tightly spaced because of the absence of serifs.

John, which sans was tested in the research about lateral masking? The reason I ask is that I suspect the reason for the problems of letter recognnition in sans is that a balance between counter space and letter space is important for letter recognition. If the letters are wide--the 'o' more circular rather than oval--and the letters closely spaced, as in Helvetica, then I would expect the letters would be less easy to decipher. But when the letters are narrower--the 'o' is a narrower oval--then the narrower letter space of the sans would be less of a problem, and the 'lateral masking' less.

This is my effort to explain why I find Helvetica in small printed text much less readable than Gerard Unger's Vesta, or Meta for that matter. My explanation: the narrower counters balance the tighter spacing of sans faces.

I suspect that the 'knitting together' of words as units is a due to a different effect of serifs. I think the serifs help to achieve even color in the word, making it easier for the parafovea to see upcoming words as separate words, and plan for the next saccade. In other words, the parafovea can identify words as grey blocks separated by word spaces,even without being able to read the letters within the words. The set of grey blocks may be enough for planning, and highly functional.

Without the serifs, and with wide letter spacing, the grey word block is not as distinguishable from the word space. That is why, I think, you can't simply track Helvetica more widely and get a good readable text face from it. And it is why sans serifs need tighter spacing in the first place.

In other words, serifs serve two purposes: both knitting the words together visually as units and keeping the letters far enough apart in comparison to their inner spaces for easy letter recognition. In sans faces, these two different goals come into conflict, particularly for wide designs. I think even with narrow designs the horizontality of the serifs helps get better color to knit together words, but the advantage is less marked for designs with narrow counters.

Finally, I think the horizontal strokes help to tell the eye where the line of text is, so it is easier for the eye to 'hold the line', and not get confused with the next or previous line. I think that is a factor in why sans usually need more leading.

Now one of the reasons why all this is difficult to prove is that the brain can overcome all these obstacles that sans put up. But it is taxed by the effort. That is my explanation for why some faces seem friendlier and more inviting and easier to read. And also why I think Kevin Larson found that usable comprehenson was better with good typography. In other words comfort in reading--which I think you, John, were skeptical about once here--is a very real factor that makes an important functional difference, even though identifying it is quite subtle and hard to test for.

Incidentally, none of the effects I am hypothesizing here are dependent on the existence of a 'bouma' effect, such as Peter Enneson is hypothesizing--that is, a reading of whole words as patterns (including internal features of letters), rather than first identifying letters and then assembling them into words.

Perhaps we could wrap our discussion around a concrete example. Below are 4 variations on the letter n ranging from a "traditional semi serif" to a sans version. I've put them in an isolated context (a serif free zone if you will) -- the word "tone". Then I put it next to another potentially serifed letter -- in the word "tonne". Obviously these are simplified cases, but I'm curious what forms work in this specific context, based on people's notions about serifs and readability.

Note: The resolution of the image makes spacing problematic. I know this is a light weight which introduces it's own issues, but it's what i've got.

My observations:
1. The serifs do help to define the space between the n and rounds.
2. As a result tone #3 seems best to me (traditional semi serif placement)
3. One serif seems to be enough to define the space between the letters.
4. The space inside the n seems well enough defined without serifs inside.
5. It seems like the x height serifs are more critical than the baseline serifs.
6. As a result, tonne #3 seems best to me.
5. I'm making these observations as a designer in a meta context not a reader immersed.

very interesting. i think you're quite right about the serifs on the inside being superfluous. i might have to steal some of your ideas for some changes to my interloc. i wanted to accomplish something like what you described with that face, but it seems you have it much more thought out! thanks for sharing your developments with us.

This is always the case and is the real job of "Type Face" design vs. "Letter series" design. The Yin Yang of design where one needs the other so much that they help define each other. If you think about ambigrams, you get at the notion. You cannot ignore one in favor of the other.

This is exactly what I was after last year when working on my Leporello type face. I was attempting to design a sans with enough appendages to solve some of the reading issues but never went as far as to make it a semiserif face. Most of the discussion in the critique was involving the stylistic quarks that come about by doing this. I wonder about the difference with showing the kind of face you are talking about to a naive audience rather than type Design people who perhaps know too much about how type has looked since its inception? I know that when I showed text set in Leporello to naive viewers, they never noticed the quirks.

I think, besides the serif, another element which contributes to readability is stroke modulation. High contrast is a problem that can't be forgotten. I should think. Helvetica and Didot both aren't friendly to the eyes.

Paul, your second ton and tonne look better, but here you are following the traditional way an italic would be done, so they conform more to reader expectations.

Another issue here is the narrowness of the letters and of the sidebearings.

Randy, on your example, one could get the total sans case to have more even color, similar to the more serifed version, by pulling in the side bearings appropriately. So the issue isn't just serifs but also spacing. If you start deleting or adding serifs depending on context, you would probably want also to play with the spacing according to context, when you add or substract the serif. This might get more complicated than it's worth. Still, I think it is an interesting exploration, and you may well come up with something very nice. Good luck!

Paul: My observations on my effort apply to yours too. I don't think you need the interior serif, but you will need to look at your glyph proportions. Hacking off a serif changes the size of the counter significantly. Spacing looks tight for text, but it's hard to say in this context. Pretty sure it will need to loosen. Your nn combo with two serifs may make sense in the context of your design (which is much closer to serif type than sans). In mine, i'm trying to add the minimum to maintain as much sans feel ... hence tonne #3

William: Removing a serif from the outside also shrinks the apparent size of the counter, though less than removing a serif inside (see above). In the sample, I did adjust the spacing (didn't simply whack off a serif), but I didn't slightly widen the sans version (which I should).

Chris: In Leporello you were approaching readablility by looking at glyph structure itself. What I hope to accomplish to keep glyph structure as consistent (normal?) as possible, and to isolate the effect of the serifs. This is for my own sanity. If you change too many things, you loose the cause of your effect.

Re: naive audience rather than type Design people

Since quirks will be limited to serif placement, how quirky the face appears will depend on the OT rules applied. The idea is to create n.full, n.xht, n.base, n.sans sets for the lower case (where applicable), and test various observations like I made above. So I'll be changing the rules instead of changing the glyphs themselves. Hopefully this will add a level of detatchment about normalness. In otherwords, I'll try to turn off the voice that says: "it's readable, but is it marketable?" To be honest, I don't think even the craziest placement would fall too far out of the mainstream.

Tiffany: The modulation here is looking more toward the helvetica end of the spectrum, though not as monoline or vertical. As the weights get heavier I plan to apply more contrast. The glyph structures in this light version should hint at what is to come though. There is a definate diagonal stress.

Randy,
It would be fantastic to isolate the variable. I hope you can do it successfully. This would be a prime candidate for a meaningful readability research experiment. By changing your parameters in your opentype feature, you could generate the same text with different serif removals and see what the effect would be to the reader. This would perhaps generate more insight on the serif's role in long duration reading. It would be nice if someone would give you a grant to test it. You could include some straight sans, serif, and semiserif faces as controls and measure your degree of readability enhancement with your experimental face.
BEST OF LUCK TO YOU on this!!!

William: John, which sans was tested in the research about lateral masking?

The lateral masking research to which I referred was not testing typefaces per se. Peter Enneson sent me the information, and I'll need to dig around in my notes to find it. The tests were using shapes of various kinds, first isolated, then adjacent to other shapes, and then with connecting strokes to adjacent shapes. Participants were better able to identify the shapes in the parafovea in the latter case, which surprised the researchers. My observations about serifs are an inference from this study, but obviously a lot more study needs to be done, and specific testing of typefaces should be done to confirm the inference.

I don't recall every being skeptical about the importance of comfort in reading. It seems to me very important. Eye-strain is one of the most easily quantifiable aspects of readability testing, because it is possible to measure the activity of the relevant muscles.

Your comments about the relationship of internal and interletter spacing in sans serifs are absolutely right (have you read The Stroke yet? this is illustrated very well). But this addresses the question of why one kind of sans serif, spaced in a particular way, may be more readable than another kind of sans serif spaced in a different way. It doesn't address the point of the serif.

You could include some straight sans, serif, and semiserif faces as controls
If I was a researcher, what I would do is start with Thesis (The Serif and The Sans and The Mix). Then modify The Mix as I've described and add the opentype. This would save a weary type designer a heck of a lot of time (but might violate a EULA). The benefit is that you have the same typeface, further reducing your variables.

As it is, I'd like to draw a nice reading sans (semi) using all the resources available.

I think Tiffany has an important point that is useful to consider: in developing a test typeface with enough variants to isolate the serif's effects, wouldn't it be useful to settle on a letterform that, at text weights, can accomodate sans as well as serif structure, i.e. a moderate-contrast thing like Schneidler, Chaparral or Joanna?

Then, too, there are other choices you would face, like, do I deny the possible importance of diagonal stress and make the thing all vertical like Baskerville or Cheltenham? Throw out the ideas that Bloemsma was getting at?

Then, how to filter out the variable of width? It's true that not only spacing but letter widths should change as well depending on serif presence.

But also, proportions between letters must have an effect on reading comfort; surely monospaced type is not optimal, but then too much width contrast also hinders reading comfortably.

Rather than enumerate the variables, I guess I'm saying that if you want to test the usefulness of serifs, it may require more complex, interlinking factors than simply which serifs are present. What assumptions do you start with? Obviously Helvetica and Didot are not candidates. So many things affect readability that it might be necessary to test existing faces that are related but differ in one aspect, like contrast, and come to some conclusion about the ideal contrast level. Then, test faces with the same contrast level and differing amounts of diagonal stress. Determine the optimal diagonal stress. Then test faces with optimal stress and contrast with different widths.....

Of course if you start that kind of elimination with serif faces, find "the one" most readable, and chop off a few serifs, it might fall apart..... Back to square one?

what will happen to your serifs as the weight increases
As the weight increased the contrast will also increase. Light to bold, they will keep the wedge shape, and be analagous to the thins (slightly thinner). Above that we are not really talking about extended text so It might get funky. I'm not sure. I can say it won't be a straight interpolation light to überblack, with correspondingly übermonster case of the slabbies.

Carl: I think using a font with moderate contrast is a good idea. And I agree about reducing as many variables as possible. Hence my above example of Thesis. While you may not see many books set in The Serif, you could probably still find out about how serifs are functioning using a design normalized by a skilled typeface designer across styles such as Thesis. Certainly with better results than a researcher-turned-typedesigner's attempts at Times Roman Sans mentioned above. (Chris: This is the original Sans of Times!)

Anyway. My teachers allways said that the serif's draws a baseline, and that makes it easier to read in long texts. And that's also what some books say.
But in my point of view the thing making it easyer to read is that the letters become more equal in width with serif's.
The i, l, j and so on become wider. But letters like o stays the same.

So "ioi" looks better in serifs than in sans. Serifs evens out the white space.

Lasse, interesting observation about the ilj. These three letters are given serifs in FF Info Display. I think it idea was to make them easy to differentiate from each other and the cap I, but this would be an additional benefit.

John, I finally got my (cheap) Amazon USA copy of 'The Stroke'. The illustration you referred to, on p. 42-43, is just brilliant. It really settles the argument as to the importance of the ratio of interletter space to counter space. An additional factor he doesn't go into, but which I think is important is the influence of the weight of the letters on ideal spacing. These all interact with the influence of serifs.

The interaction of different factors is I think why Randy's inquiry is tough. It isn't only the presence or absence of serifs, but also the *ratios* of stroke weight, size of counters and inter-letter spacing. And Lasse's insight raises the question of whether there are special issues for narrow letters.

Hi Hrant, don't you think that it's divergence (of width in this case) within a limited spectrum that's most likely to be easily processed as pattern? Such that widening i and l with serifs brings outliers into a width-range over which differences are more readily picked up?

James also mentions above the Swanson book, which I've read; apart from Rolf Rehe's and your essays (and perhaps one or two others I've forgotten) it's the most astonishing rubbish, semi-literate garbling of continental philosophy. What were you thinking in associating yourself with these dismal frauds?

There certainly are limits. But the main
thing is to see that divergence provides
the information, not convergence.

> within the constraints of even of color and good rhythm

Even color: Here again I have to point out that even color,
perhaps only because of the wording, tends to convey the need
for total uniformity, which is something we can hopefully agree
is a Bad Thing. So when you say "within the constraints", I hope
it's clear that even color is just another factor that needs to be
balanced, not some sort of absolute requirement.

Rhythm: I'll kindly let that slide this time. :-)

--

Graphic Design & Reading: Well, I was, and still am, actually
flattered to have been asked by Gunnar to contribute. I'm also
grateful in a practical sense, because for some reason it seems
I only write articles when somebody asks me to, and then I have
something useful to brandish. The pseudo-philosophy you complain
about was the hallmark of the 90s... and GD&R came out towards
the end of that era. Actually, I didn't know what else would end
up in that book; but even if I did I would have gone ahead with it:
it was a great opportunity to reach a lot of people; in fact a quarter-
length version of that essay (with a really good Spanish translation
by Jorge de Buen) was subsequenly published in tipoGrafica. BTW, a
lot of people think MINE was the rubbish part! :-)

a lot of people think MINE was the rubbish part!
It's a superb piece, and I'd love to see whether divergence in incunable-style micro-properties can work as well as the macro-divergence of your example lowercase (on the grounds that the reduced clarity of vision in the parafovea isn't really gaussian - there's no certainty that different architectural forms are more clearly perceived than things like different lengths of serif or different relationships between internal and external axes). As for colour, I do find consistently divergent colour very off-putting in, say, the light s of the original California Old Style or the light h of digital Poliphilus, but perhaps if divergent colour were spread more evenly across the alphabet it wouldn't matter so much.

Color spikes: I think if they're mild enough (and yes, spreading
the divergence around is crucial*) so as not to trigger errant
saccades (saccades from anything except the previous fixation)
then they can only help.

* Could one say that the mathematical derivative
of the color map should be totally even? Hmmm...